1 files changed, 25 insertions, 63 deletions

diff --git a/bzipper_macros/src/discriminant/mod.rs b/bzipper_macros/src/discriminant/mod.rs
index 21a835a..a5d6a95 100644
--- a/bzipper_macros/src/discriminant/mod.rs
+++ b/bzipper_macros/src/discriminant/mod.rs
@@ -1,98 +1,60 @@
 // Copyright 2024 Gabriel Bjørnager Jensen.
 //
-// This file is part of bzipper.
+// This file is part of bZipper.
 //
-// bzipper is free software: you can redistribute
+// bZipper is free software: you can redistribute
 // it and/or modify it under the terms of the GNU
 // Lesser General Public License as published by
 // the Free Software Foundation, either version 3
 // of the License, or (at your option) any later
 // version.
 //
-// bzipper is distributed in the hope that it will
+// bZipper is distributed in the hope that it will
 // be useful, but WITHOUT ANY WARRANTY; without
 // even the implied warranty of MERCHANTABILITY or
 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 // Lesser General Public License for more details.
 //
 // You should have received a copy of the GNU Less-
-// er General Public License along with bzipper. If
+// er General Public License along with bZipper. If
 // not, see <https://www.gnu.org/licenses/>.
 
 use proc_macro2::TokenStream;
 use quote::ToTokens;
+use syn::{Expr, Lit};
 
 /// An enumeration discriminant.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
 #[repr(transparent)]
-pub struct Discriminant(u32);
+pub struct Discriminant(pub isize);
 
 impl Discriminant {
-	/// Constructs a new discriminant.
-	#[inline(always)]
-	#[must_use]
-	pub const fn new(value: u32) -> Self { Self(value) }
-
-	/// Retrieves the raw discriminant value.
-	#[inline(always)]
-	#[must_use]
-	pub const fn get(self) -> u32 { self.0 }
-
-	/// Unwraps the given value as a discriminant.
+	/// Parses the expression as a discriminant value.
 	///
 	/// # Panics
 	///
-	/// If the given value cannot be represented as an `u32`, this function will panic.
-	#[inline(always)]
+	/// This constructor will panic if the provided expression is not a valid `isize` literal.
+	#[inline]
 	#[must_use]
-	pub fn unwrap_from<T: TryInto<Self>>(value: T) -> Self {
-		value
-			.try_into()
-			.unwrap_or_else(|_| panic!("enumeration discriminants must be representable in `u32`"))
-	}
-
-	/// Unsafely unwraps the given value as a discriminant.
-	///
-	/// This function assumes that this conversion is infallible for the given value.
-	/// If this is a false guarantee, the [`unwrap_from`](Self::unwrap_from) function should be used instead.
-	///
-	/// # Safety
-	///
-	/// Behaviour is undefined if the given value cannot be represented as an object of `u32`.
-	#[inline(always)]
-	#[must_use]
-	pub unsafe fn unwrap_from_unchecked<T: TryInto<Self>>(value: T) -> Self {
-		value
-			.try_into()
-			.unwrap_unchecked()
-	}
-}
-
-impl ToTokens for Discriminant {
-	#[inline(always)]
-	fn to_tokens(&self, tokens: &mut TokenStream) { self.0.to_tokens(tokens) }
-}
+	pub fn parse(expr: &Expr) -> Self {
+		let Expr::Lit(ref expr) = *expr else {
+			panic!("expected literal expression for discriminant value");
+		};
 
-impl From<u32> for Discriminant {
-	#[inline(always)]
-	fn from(value: u32) -> Self { Self(value) }
-}
+		let Lit::Int(ref expr) = expr.lit else {
+			panic!("expected integer literal for discriminant value");
+		};
 
-impl TryFrom<usize> for Discriminant {
-	type Error = <u32 as TryFrom<usize>>::Error;
+		let value = expr.base10_parse::<isize>()
+			.expect("expected `isize` literal for discriminant value");
 
-	#[inline(always)]
-	fn try_from(value: usize) -> Result<Self, Self::Error> { value.try_into().map(Self) }
-}
-
-impl From<Discriminant> for u32 {
-	#[inline(always)]
-	fn from(value: Discriminant) -> Self { value.0 }
+		Self(value)
+	}
 }
 
-impl TryFrom<Discriminant> for usize {
-	type Error = <Self as TryFrom<u32>>::Error;
-
+impl ToTokens for Discriminant {
 	#[inline(always)]
-	fn try_from(value: Discriminant) -> Result<Self, Self::Error> { value.0.try_into() }
+	fn to_tokens(&self, tokens: &mut TokenStream) {
+		self.0.to_tokens(tokens);
+	}
 }